Relationship between serum osteocalcin levels and glucolipid metabolism in elderly type 2 diabetic patients with non-alcoholic fatty liver disease

Abstract

Objective To explore the relationship between serum osteocalcin levels and glucolipid metabolism in elderly type 2 diabetic patients with non-alcoholic fatty liver disease(NAFLD). Methods Data collected from 97 patients with type 2 diabetes mellitus(T2DM)admitted to the Department of Geriatric Endocrinology of the First Affiliated Hospital of Zhengzhou University from June 2014 to April 2015 were retrospectively analyzed.Patients were divided into the T2DM group(type 2 diabetic patients without NAFLD, n=47)and the NAFLD group(T2DM patients with NAFLD, N=50). Healthy elderly subjects(n=30)from the same period served as the control group.Body mass index(BMI), osteocalcin, fasting blood glucose, fasting insulin, homeostasis model assessment for insulin secretion index(HOMA-β)and insulin resistance(HOMA-IR), glycosylated hemoglobin(HbA1c), total cholesterol, triglyceride, high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C)were compared between the 3 groups. Results Levels of fasting blood glucose, fasting insulin, HbA1c, total cholesterol, triglyceride, LDL-C and HOMA-IR were higher, while levels of HDL-C, HOMA-β and osteocalcin were lower in the T2DM and NAFLD groups than in the control group(all P<0.05). Levels of BMI, fasting glucose, fasting insulin, HbA1c, total cholesterol, triglyceride, LDL-C and HOMA-IR were higher and levels of osteocalcin were lower in the T2DM group than in the NAFLD group(all P<0.05). Pearson correlation analysis showed that the osteocalcin level was negatively correlated with fasting blood glucose, HbA1C, HOMA-IR and BMI(r=-0.701, -0.442, -0.337 and -0.543, P<0.05 or P<0.01), and positively correlated with HOMA-β(r=0.341, P<0.05)in the NAFLD group. With serum osteocalcin as the dependent variable, multiple linear regression results showed that fasting blood glucose was an independent influencing factor for serum osteocalcin(β=-1.57, P<0.05)in the fatty liver group. Conclusions Serum osteocalcin levels significantly decrease in elderly T2DM patients with NAFLD, are closely correlated with glucolipid metabolism, and may have some important clinical significance in the prevention and treatment of NAFLD in elderly patients with type 2 diabetes. Key words: Osteocalcin; Diabetes Mellitus, Type 2; Fatty Liver